The invention herein described was made in the course of or under a contract with the Department of the Air Force.
1. Field of the Invention
The present invention relates to receiver protectors for radar, and especially to receiver protectors for types of radar requiring a quick recovery period following the transmitted radar pulse, such as is the requirement in the case of pulse doppler radars.
2. Description of the Prior Art
Since the advent of the tritium primed power limiter device a method has been sought to eliminate the long recovery period of the device. The cause of this long recovery period is the fact that the tritium primer must be immersed in a semi-inert gas environment such as an admixture of argon (A), ammonia (NH.sub.3), and water vapor (H.sub.2 O). The primers cannot survive when immersed in an attaching gas such as chlorine, which provides extremely short recovery times. On the other hand, an A+ NH.sub.3 + H.sub.2 O gas fill yields a long recovery time and therefore degrades radar performance at short ranges.
One known approach for reducing the recovery time of tritium primed power limiters is the inclusion of water vapor in the admixture of semi-inert gases. An inherent disadvantage of doing this is that it raises the lower limit of the equipment's range of operating temperature. This is an important factor where the radar may be housed in structures which are subjected to extremely low temperatures, such as those installed in aircraft borne radomes.